The interesting thing about this campaign is that it shows how strangers are far more complimentary about how people look than those people would be about themselves. We know our own perceived flaws far better than anybody else does; in our culture of image obsession, it is far too easy to assume that every person in the world is judging you for every little imperfection on your face and of your body.
There have absolutely been experiments conducted about people's self-perceptions as compared to others' perceptions of them. This is nothing new. But it's far more interesting to look at than your average psychological study, and since it's not saying anything especially groundbreaking – does anybody really think strangers would be more critical of a woman than that woman would be of herself? – "interesting to look at" is what matters.
No, it asserts that. It does not show it. To show it would require a valid methodology.